4-(5, 6-di-substituted oxy benzotriazole-2-yl) stilbenesulfonic acid brighteners and ethods for making same



United States Patent 3 410 847 4-(5,6-DI-SUBSTITUTED O XYBENZOTRIAZOLE-Z- YL) STILBENESULFONIC ACID BRIGHTENERS AND METHODS FORMAKING SAME Albert F. Strobe], Delmar, and Sigmund C. Catino, Castleton,N.Y., and Leon Katz, Springfield, N.J., assignors to GAF Corporation, acorporation of Delaware No Drawing. Filed Feb. 9, 1965, Ser. No. 431,442

6 Claims. (Cl. 260-240) This invention relates to new, useful andoutstanding stilbene triazole compounds, and in particular,di-substituted oxy benzotr-iazolyl stilbenesulfonic acid compounds withtheir outstanding optical brighteners or whitening agents.

It is well known that textiles tend to develop a yellowish shade onaging which cannot be removed by ordinary methods of bleaching orwashing. The heretofore used methods of bluing white mtaerials with bluepigments or fugitive blue dyestufis have become quite obsolete in modernlaundry practice and have been largely superseded by methods employingfluorescent optical bleaching agents or brighteners as additives to thesoap or detergent in the washing bath. These brightening agents areusually conveniently supplied commercially in the form of intimateadmixtures with the soap or detergent in bars, flakes, powders, etc. Thefluorescent optical bleaching agents perform their desired function byvirtue of their characteristic absorption of ultra-violet radiations andsubsequent conversion of this energy to light energy within the visiblespectrum. This converted and emitted light energy tends to neutralizeany yellowness of the material and thereby increase the apparentwhiteness thereof.

Since the predominant textile material in conventional laundry practiceis cotton, brightening agents for use in laundering operations inconjunction with the conventional detergents are generally characterizedby the pres ence of ionic or water-solubilizing groups which arepreferably sulfonic acid groups in order to obtain the necessaryafiinity for the cotton material. Such compounds may or may not also beeliective with other synthetic textile fibers such as nylon and acetaterayon and the like, and while this is obviously desirable in manyinstances, such ionic brighteners which are useful with cotton may onlybe partially satisfactory with nylon and the like.

Com-pounds which have been suggested and employed as fluorescentbrightening agents include the following:

(I) Acylated derivatives of 4,4'-diamino-stilbene-2,2'- disulfonic acid.

(II) Triazyl derivatives of diamino stilbene disulfonic acid.

(III) Acylated derivatives of diamino dibenzothiophene dioxide, etc.

Compounds of Type I are disclosed in US. 2,581,059 and 2,643,198 and inBritish Patent 584,484.

Compounds of Type II are disclosed in US. Patent 2,618,636 and inapplication Ser. No. 381,856 published May 11, 1954 by the ARC.

Compounds of Type III are exemplified in US. Patents 2,563,493 and2,563,975.

In addition to the types mentioned above, other triazyl compounds havebeen suggested. Thus US. Patent 2,713,- 054 discloses monotriazoles ofthe type:

lllaOsS In addition to compounds of the above type, there have also beenpatented stilbenenaphthotriazoles containing ionic groups such as areshown in US. Patent 2,784,- 183 and a representative compound therein isthe following:

In US. Patent 2,993,892, there are disclosed ionicstilbenenaphthotriazoles of the following formulas:

as. N Q Q \i/ SOaNa There are numerous other disclosures relating tostilbenemonotriazoles as well as other stilbene compounds which areuseful as brightening agents for fibers other than cotton, particularly,and which compounds do not necessarily contain ionic groupings. Examplesof such patents are US. Patent 2,784,184, which describes compounds ofthe type:

and US. Patent 3,062,814, which exemplifies compounds of the type:

N=0H (F) in which R is selected from the group consisting of hydrogen,chloro, bromo and lower alkyl.

As evidenced by the above described prior art, there is tremendousactivity in the area of brightening agents suitable for use inlaundering operations for brightening textile materials and particularlycotton textiles. Such activity is primarily based upon the need anddesire as well as the constant striving for more efficient compoundswhich can do a better job of brightening at a lower cost. In addition,since normal laundering practice involves the use of chlorine bleaches,the need for brighteners which are stable in the presence of suchbleaching agents becomes of paramount concern.

It has now been discovered that a class of benzotriazolylstilbenesulfonic acid compounds containing two substituted oxy groups ina critical position in the molecule and at least one sulfonic acid groupare not only outstanding brighteners from both an esthetic point ofview, but also from an economic point of view, and in addition, suchcompounds are extremely stable in the presence of chlorine bleachingagents.

Certain of these di-substituted oXy benzotriazole brighteners haveunique brightness strength on cotton from non-ionic detergent baths inthe presence of hypochlorite. For instance, only half as much of H Ho01n l OCHa S O Na N (A) is required to produce the same whiteningeffect on cotton from commercial Ad and All, both non-ionic detergents,in the presence of sodium hypochlorite as of the most widely usedcommercial product:

It is thus in the presence of non-ionic detergents used in conjunctionwith hypochlorite bleach that the most outstanding advantages inperformance of the new compounds occur. In fact there is no commercialbrightener which has whitening eifect in this application equal to theabove described compound A at equal concentration. Further, there is nobrightener described in all the prior art compounds which has whiteningeffect in this application equal to brightener A. Thus there is nononsulfonated, mono-sulfonated, di-sulfonated, are trisu'lfonatedbrightener from all the mono-triazole, ditriazole, bis-benzoxazole,bis-benzimidazole, stilbeneamine-cyanuric amide, stilbeneamine-benzoylamide, pyrazoline, coumarin, etc. classes which hasanywhere near equal whitening power from non-ionic detergents withsodium hypochlorite on cotton.

It is therefore an object of the present invention to provide new anduseful brightening agents, and particularly brightening agents of thestilbenetriazole type.

It is another object of the present invention to provide outstandngbrighteners which are particularly adaptable for use in conventionallaundering operations for brightening textile materials, and moreparticularly cotton textiles.

It is still another object of this invention to provide new brighteningagents which are characterized as disubstituted oxy benzotriazolylstilbenesul-fonic acids which are particularly effective in conventionallaundering operations in conjunction with detergent compositions, andwhich brightening agents are outstandingly stable in the presence ofchlorine bleaching compounds.

It is still another further object of this invention to provide new andoutstanding detergent compositions containing the novel brighteningagents herein disclosed.

It is still another further object of this invention to provideprocesses for organic materials, and particularly cotton textilematerials employing the novel and outstanding brightening agentsdisclosed in this application.

It is still a further object of this invention to provide improvedbrightened organic material, and particularly cotton textile materials,by incorporation therewith the new and outstanding brightening agents ofthe present invention.

Other objects will appear hereinafter as the description proceeds.

The new brightening compounds of this invention have the followinggeneral formula:

wherein R and R are independently lower alkyl, and preferably alkyl of 1to 4 carbon atoms, carboxy lower alkyl and preferably carlboxy methyl,or together R and R may be methylene; m and n have the values 0 or andthe sum of m: and n is 1 or 2; M is hydrogen or a saltforming cation,preferably an alkali metal (sodium, potassium or lithium and the like),ammonium, or substituent ammonium such as an amine and the like.

The preferred compounds are those containing one sulfo group, and thispreferably in the benzene ring of the stilbene moiety remote from thetriazole ring. Thus, the most preferred compounds are those having thefollowing formula:

som

wherein R R and M are as defined above. Some of the specific compoundsare as follows:

I -00nr, OCHzCII COONa sO Na SO NB o I O -OCHQCOON3 SO;Na

SOaNB SOaNa OCHa CH=CHN Q -oonn SOsNa SOaNa N 0 00113 OH=CH N IOCHzCOONa l0 SOaNa SOzsNfi N I -0 some some N /I -0 04H; -on=ou- N IOCH2CH2COONZ\ SOQNZL SOaNa N oom -CH=CHN -0cn= SO3N8 14. N

/ O CzH I oo,n. SOaNa N 15. N F OCH3 I OOI-IzCOONa SO Na N /l --OH=CH--N out Q Q \I 0 I SO3N8 N The novel compounds of this invention arecharacterized by excellent fiber substantivity, particularly forcellulosic and similar hydrophilic fibers, and esthetically desirablehue, an outstanding apparent whiteness, excellent resistance tobleaching agents such as chlorine, and extremely excellent lightfastness characteristics. While the compounds are most preferred for usein detergent systems for application to the textile during launderingoperations, the compounds may, nevertheless, be employed usingtechniques for incorporation into organic material. Thus, the compoundsmay be added to spinning solutions of cellulose acetate, they may beused to impregnate paper, they may be incorporated into paper byaddition to the pulp in the beater stage or at any point prior to thedrying of the paper, and they may, in general, be added to waxes, gums,resins and the like to effect a whitening thereof.

The compounds of this invention are prepared generally in theconventional manner known to the art which involves coupling adiazotized sulfo stilbene to the selected substituted dioxyanilinecompound and thereafter oxidizing the resultant azoamino compound to thecorresponding triazole. The procedure for the latter oxidation may varydepending upon the choice of the oxidizing agent. For example, when oneuses ammoniacal (or other organic base, e.g., pyridine, etc.) coppersulfate as the oxidizing agent, the resultant by-products of suchreagent may be removed by adjustment of the pH of the solution, i.e.,the reduction products of the oxidizing agents may be solubilized bymaking the solution more acidic, so that the by-products are removed inthe filtrate by a filtration step. Alternatively, the lay-products maybe removed in the filtrate by making the reaction medium alkaline withammonia (pH 11) prior to filtration. While it is preferred to usemetallic (ic-ous ozidizing agents such as copper sulfate, ferricchloride, ferric NH SO do, one may also employ hydrogen peroxide, KMnO KCr O CaCOl, Na perborate, oxygen, etc.

The following examples will serve to illustrate the present inventionwithout being deemed limitative thereof. Parts are by weight unlessotherwise indicated.

Example 1 Preparation of:

24 g. of 4'-amino-2-stilbenesulfonic acid (0.087 mole). 500 ml. waterand 8.6 cc. NaOH (40% wt./vol.) are mixed at 40 C. to give a pH of 8.5..17.4 cc. NaNO (38% aqueous solution) are then added slowly. This is thenpoured slowly over a 1 hour period into a mixture at 5-10 C. of 240 cc.water, 1.4 cc. NaNO (38% aqueous solution) and 27 ml. HCl in an icebath. After stirring 2 hrs. at 510 C., excess nitrite is destroyed with7 mls. sulfamic acid (10% aqueous solution). 14.7 g. of vacuum distilled3,4-dimethoxyaniline is dissolved in 100 mls. acetic acid and addedslowly at 5-l0 C., stirred 1 hr., then made faintly Congo blue byaddition of 48 g. sodium acetate. After stirring over night it is madeCongo neutral by the addition of sodium acetate, then filtered, washedwith 500 mls. 3% HCl, 500 mls. water and 200 cc. isopropanol to give 72g. of product.

36 g. of this product, 200 ml. picoline, 100 ml. water and 20 ml.ammonium hydroxide (concentrated) are mixed and heated to solution at 95C. T 0 this is added 27.25 g. CuSO .5H O in 50 ml. water. The mixture isstirred 2 /2 hrs. at 95 C., cooled to C. and treated with 75 ml. sodiumsulfide (20% Wt./vol.). The material is filtered at C. and washed with a3% picoline-inwater solution. The pH is adjusted to 9 by addition ofaqueous sodium carbonate solution (20%), steam distilled, cooled to 75C., then filtered, Washed with ml. Warm water and air dried at 80 C. Thefinal product has a K =l33 at 358 m Example 2 To demonstrate theoutstanding brightening action of the compound of Example 1, it iscompared in a standard laundering operation with detergent with otherbrighteners, all at equivalent K value concentrations at the maximumabsorption points of each of the compounds. A K value=80 is selected asthe comparison point since each of the compounds tested has a K value atthe maximum absorption in excess of this value and the purpose forcomparing the compounds at equivalent K values is to obviate thepossibility that the compounds may not be in their most absolutely purestate which would necessarily be a requirement for a meaningfulcomparison on a weight basis. The general procedure for testing thecompounds is as follows. 50 mg. of brightener compound is dissolved in10 ml. of dimethylforrnamide and then drowned into 1 liter of water. Aproper aliquot is then taken to give the desired brightenerconcentration on a percentage basis at a K=80 concentration. To alaunderometer bath containing 1 g. of All (a nonionic ethyleneoxide-phenolic condensate) in 500 ml. of water at F., there is added theselected amount of brightener and 10 ml. of sodium hypochlorite solutioncontaining 0.2% available chlorine. After standing 1 minute, a 5 g.swatch of cotton cloth is immersed in the bath and the launderometercontaining the slurry of detergent and cotton cloth is agitated for 20minutes at 120 F., after which the cloth is removed, rinsed in clearwater, and dried.

i SO3NB yields a product with a brightness value of 66. Thus, it isclearly seen that even though 50% more of the second .brightener isused, a significantly lower brightness is obtained than with thebrightener of Example 1.

Example 3 Example 2 is repeated except that in place of All, thedetergent employed is Alfionol, a biodegradable nonionic compound basedon the reaction of ethylene oxide and an aliphatic alcohol. Again, withboth brighteners (that is, of Example 2), at equal K values of 80, thebrightener of Example 1 gave a reading of 68 when used at aconcentration of 0.0032% based on the weight of the fiber whereas thecommercial brightener (i.e., the sulfostilbylnaphthotriazole shown inExample 2) gives a brightness value of 59 at a concentration of 0.0064%(based on the weight of the fiber). Again, it is clearly apparent thatwith only half as much of the brightener of Example 1 as compared withthe commercial brightener, a distinctly higher brightness value isobtained.

Example 4 and the resultant swatch has a brightness value of 65. Thisdemonstrates that the compound of Example 1 is an efiective inbrightness characteristics at a concentration 50% less than is necessaryusing a somewhat similarly related compound which is disclosed in US.Patent 2,713,057, and specifically covered by claim 2 of this patent.

OCH

Example 5 Example 2 is again repeated employing the compound of Example1 at the same concentration used in Example 2 and in place of thecommercial brightener comparison of Example 2, there is used 0.0064%based on the weight of the fiber of the compound of the formula:

N ooH3 NHCOCH S OaNa N/ which compound is described in Example 4 of US.Patent 2,713,057. The All of Example 2 is replaced by Tide (anionicalkyl aryl sultonate). The swatch laundered with the compound of Example1 has a brightness of 87 whereas the swatch laundered with the com- 8pound of Example 4 of US. Patent 2,713,057 has a value of 32.

Example 6 Preparation of:

s O Na N This compound is prepared in the same manner as Example 1 withthe exception that the 3,4-dimethoxyaniline is replaced by 16 g. of3-methoxy-4-ethoxyaniline.

When applied to cotton in the manner of Example 1 the results arecommensurate.

Example 7 Preparation of:

This compound is prepared in the manner of Example 1 with the exceptionsthat the 4-amino-Z-stilbenesulfonic acid is replaced by4-amino-2-stilbenesulfonic acid and the 3,4-dimethoxyaniline is replacedby 19 g. 3,4-methylenedioxyaniline. When applied in the manner ofExample 1 commensurate results are obtained. This compound has a K=l38.8 at 358 my.

Example 8 Preparation of:

N OCHzCOONa 1 -0 onto 0 0 Na S O sNa N This compound is prepared in themanner of Example 1 with the exceptions that the4'-amino-2-stilbenesulfonic acid is replaced by4-amino-2-stilbenesulfonic acid and the 3,4-dimethoxyaniline is replacedby 21 g. 1,2-(4- aminophenylene)bisoxyacetic acid. When applied in themanner of Example 1, excellent results are obtained. This compound has aK =76 at 355 m is produced in known manner by treating an equimolaramount of Z-methoxy-S-nitrophenol with chloracetic acid and reducing.The brightener is then produced in the manner of Example 1 with theexception that the 3,4- dimethoxyaniline is replaced by 14.9 g. of3-amino-6- methoxyphenoxyacetic acid. When applied in the manner ofExample 1, commensurate results are obtained.

Example 10' Preparation of:

This compound is prepared similarly as in Example 1 with the exceptionthat the 4-amino-2-stilbenesulfonic acid is replaced by4-amino-Z-stilbenesulfonic acid. When applied to cotton in the manner ofExample 1 the results are excellent.

Example 11 Preparation of stilbenedisulfonic acid. When applied tocotton in the manner of Example 1, excellent results are obtained.

Example 12 Example 6 is repeated except that 4'-amino-2-stilbenesulfonicacid is replaced by 4-amino-2-stilbenesulfonic acid. Excellent resultsare obtained when applied to cotton following the procedure of Example1.

Example 13 Example 11 is repeated except that the 3,4-dimethoxyanilineis replaced by 3-methoxy-4-ethoxyaniline. Excellent results are obtainedwhen applied to cotton by the procedure of Example 1.

Example 14 The preceding example is further repeated except that inplace of the aniline thereof, an equivalent weight of 3,4-methylenedioxyaniline is employed.

Example 15 The preceding example is further repeated except that theaniline compound used is an equivalent weight of1,2-(4-aminophenylene)bisoxy acetic acid.

Example 16 The procedure of Example 9, is repeated except that in placeof the stilbenesulfonic acid of that example, an equivalent amount of4-amino-2,2'-stilbenedisulfonic acid is used.

While several of the above examples demonstrate the use of the compoundsof this invention for brightening of cotton material, it is clear thatsuch compounds may be used generally for brightening cellulosicmaterials and cellulose derivative materials as well as other textileproducts also. The compounds may further be employed with any organicsubstrate to improve the brightness thereof. The amount of brightener tobe used is not critical, and may be varied Within wide limits. As littleas 0.001% has been found to give eifective results with the upper limitbeing goverened solely by practical considerations of compatibility andprice. In general, it has been found that no more than by weight basedon the weight of organic material is necessary under the most adversecon ditions. When the compounds of this invention are used inconjunction With detergent products, it is advantageous to employ thebrighteners in amounts ranging from about 0.1% to about 3% by weightthereof based on the weight of the detergent material.

Other variations in and modifications of the described processes whichwill be obvious to those skilled in the art can be made in thisinvention without departing from the scope or spirit thereof.

We claim:

1. A compound of the free acid form of the formula:

| (S 03M) n (SOa Dm N wherein R and R are carboxy lower alkyl; m and nhave values from 0 to 1 and the sum of m and n is at least 1; M is amember selected from the group consisting of hydrogen and a salt-formingcation.

2. A compound in the free acid form of the formula:

(SO3M).. (OsMLn wherein R is lower alkyl and R is carboxy lower alkyl; mand n have values from 0 to 1 and the sum of m and n is at least 1; M isa member selected from the group consisting of hydrogen and asalt-forming cation.

3. A compound in the free acid form of the formula:

wherein R and R together are methylene; m and n have values from 0 to 1and the sum of m .and rt is at least 1; M is a member selected from thegroup consisting of hydrogen and a salt-forming cation.

4. A compound of the formula:

N\ /O CH=OH N i Q C...

S0311 \N 0 5. A compound of the formula:

JOHN D. RANDOLPH, Primary Examiner.

1. A COMPOUND OF THE FREE ACID FORM OF THE FORMULA: